Local Anesthesia Review and Update. Dr. Julius N. Manz NMDHA Scientific Session 2013

Transcription

1 Local Anesthesia Review and Update Dr. Julius N. Manz NMDHA Scientific Session 2013

2 Disclosure I am not paid by, nor do I hold any financial interest in any of the devices or materials being presented in this lecture today

3 What we are covering Gow Gates Mandibular Block Injection Computer Controlled Local Anesthetic Delivery & the Anterior Middle Superior Alveolar Injection Oraverse - Local Anesthesia Reversal Onset - Local Anesthesia Sodium Bicarbonate neutralizing solution Kovacaine Mist TM - Intranasal Dental Anesthetic

4 The FEAR of PAIN The PAIN of FEAR

5 So what are we afraid of?

6 1. Snakes What are we afraid of

7 2. Spiders What are we afraid of

8 What are we afraid of 3. Confined Spaces

9 What are we afraid of 4. Public Speaking

10 5. Heights What are we afraid of

11 6. The Dark What are we afraid of

12 What are we afraid of 7. Thunder and Lightning

13 8. Flying What are we afraid of

14 9. Dogs What are we afraid of

15 10. Dental Care What are we afraid of

16 The Greatest FEAR our patients have is PAIN

17 We are judged by our patients on two primary criteria: #2 Did we cause them pain during treatment #1 Did we give a painless injection

18 The Pain Threshold Affected by: Sleep deprivation Stress Fear Age Gender Culture Socio-economic status Pain (chronic or acute) Patient may over-react to stimulation or interpret nonpainful stimuli as painful

19 Hyperresponders Fear of dentistry Sleep-deprivation Long-term chronic pain Short-term acute pain

20 Getting the Shot is the most traumatic part of the dental experience

21 Local Anesthetics are the SAFEST and MOST EFFECTIVE drugs in medicine for the Prevention and Management of Pain If a Local Anesthetic drug is deposited close to a nerve it WILL produce pain control 2013 Dr. Stanley F. Malamed

22 So. If Local anesthetics are so effective, then why is achieving effective pain control elusive on occasion?

23 NB vs. Infiltration All of the Local Anesthetics provide a longer duration of both soft and hard tissue anesthesia when administered via a Nerve Block (NB) then by infiltration Local Anesthetic Nerve Block (duration) Infiltration (duration) Mepivacaine plain (3%) 60 min min Prilocaine plain (4%). 60 min ~10-20 min Bupivacaine + epi (0.5%) ~up to 12 hours ~60-90 min

24 Redheads are more difficult Anesthetic requirement is increased in Redheads

25 Time of day Teeth are most sensitive in the morning and become less sensitive in the afternoon Chronobiology and Anesthesia Dominique Chassard, MD, PhD, Bernard Bruguerolle, MD, PhD Anesthesiology 2004; 100:

26 Mandibular Anesthesia The IANB (Halsted approach) has the lowest success rate of all major nerve blocks administered in medicine, and it is the single most common injection administered daily in dentistry The density of the cortical plate prevents successful administration of supraperiosteal anesthesia The lack of consistent landmarks The thickness of soft tissue at the injection site leads to increased needle deflection Accessory innervation (may be the biggest problem)

27 Mandibular Anesthesia The thickness of soft tissue at the injection site leads to increased needle deflection

28 Mandibular Anesthesia Accessory innervation may be the biggest issue Common with mandibular molars Distinct separate branch of the IA n. Buccal Lingual Auriculotemporal If accessory innervation connects to the main nerve trunk in the pterygomandibular space superior to the mandibular foramen then repeated deposition of local anesthesia at the site of the IANB will be unsuccessful Daniel Haas, DDS, PhD Alternative mandibular nerve block techniques, JADA 142(9suppl) Sept 2011

29 Mandibular Nerve Block: Gow-Gates Technique True mandibular nerve block Sensory anesthesia to V 3 George Albert Edwards Gow-Gates ( ) Advantages Greater success than IA Lower positive aspiration rate (less vascular) No problems with accessory innervation

30 Cool Mandibles

31 Mandibular Nerve Block: Gow-Gates Technique Disadvantages Difficult to teach old dogs new tricks Nerves anesthetized IA, mental, incisive, lingual, mylohyoid, buccal (75%), auriculotemporal Areas anesthetized Mandibular teeth to midline, buccal soft tissue, anterior 2/3 of tongue, floor of mouth, lingual soft tissue, body of mandible and inferior portion of ramus, skin over zygoma, posterior cheek and temporal region

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33 Mandibular Nerve Block: Gow-Gates Indications Technique Procedures on multiple mandibular teeth, buccal soft tissue anesthesia needed, lingual soft tissue anesthesia needed, lingual anesthesia needed, when IA nerve block is unsuccessful Contraindications Infection or inflammation in area of injection, patients who might bite lip and tongue, patients who cannot open wide (trismus)

34 Mandibular Nerve Block: Gow-Gates Advantages Technique One injection (vs. IA and buccal) 75% Higher success than IA (with experience) Minimum aspirations (2%) Fewer post-injection complications Successful anesthesia where a accessory innervation exists

35 Mandibular Nerve Block: Gow-Gates Disadvantages Technique Lingual and lower lip anesthesia is uncomfortable Longer time for onset of anesthesia than IA 5 min vs. 3 min (larger nerve trunk, more distance for site of deposition) Learning curve Patient remains open 1-2 minutes after injection

36 Mandibular Nerve Block: Gow-Gates Technique Technique 27 or 25 gauge long needle Area of insertion Mucous membrane on the medial of the ramus of the mandible At the height of the ML cusp of the max 2 nd molar Just distal to the maxillary second molar With the needle on a line from the intertragic notch to the corner of the mouth

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39 Mandibular Nerve Block: Gow-Gates Technique Target area Technique Lateral side of the condylar neck, just below the insertion of the lateral pterygoid muscle

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41 Mandibular Nerve Block: Gow-Gates Technique Procedure Patient supine with neck extended Patient open wide during duration Insert needle just distal to second molar at the height of the ML cusp Barrel of the syringe will be in the contralateral corner of the mouth Align syringe parallel a line from the corner of the mouth to intertragic notch and advance needle until bone is felt Usually mm above mandibular occlusal plane

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43 Mandibular Nerve Block: Gow-Gates Procedure Technique Average depth of penetration is 25 mm (similar to IA) Withdraw 1 mm, aspirate and inject 1-cartridge over 1-2 minutes Withdraw and safe needle Have patient remain open 1-2 minutes Bite block Return patient upright Wait 3-5 minutes before beginning procedure

44 Mandibular Nerve Block: Gow-Gates Technique Procedure Positive Aspiration Only 2% aspiration rate Positive aspirations generally occur in the internal maxillary artery inferior to the target area For a positive aspiration, withdraw needle slightly, angle superiorly and reinsert If bone is NOT contacted Medial needle deflection is the most common cause of failure Bring the needle tip laterally; withdraw the needle slightly and redirect by moving the barrel distally May also be caused by patient closing Utilize a bite block

45 Gow Gates Video

46 Computer Controlled Local Anesthetic Delivery (CCLAD) Advantages Designed to improve the ergonomics and precision Pen grasp vs. palm grasp Allows finger tip accuracy in needle placement Increased tactile feel Beneficial for practitioners with small hands Computer controlled flow rates and pressure Improved injection experience (less threatening to patient) Less tissue damage Less needle deflection with rotational insertion technique Automatic aspirations Disadvantages Cost Additional Armamentarium

47 The CompuDent /Wand by Milestone Scientific

48 CCLAD WAND was rated as the least anxiety producing injection instrument by patients (Kudo and associates:) Use of the WAND leads to less disruptive behavior in pediatric patients. (Gibson and associates)

49 Other CCLAD s exist

50 Anterior Middle Superior Alveolar Nerves anesthetized: ASA MSA when present Area anesthetized: Pulps of maxillary incisors, canines & premolars Buccal periodontium and bone over these teeth Palatal tissue on associated teeth

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52 Anterior Middle Superior Alveolar Indications Treatment involving the maxillary anterior teeth or soft tissue When anterior esthetic procedures are performed Muscles of facial expression and upper lip are NOT affected Supraperiosteal injection is contraindicated (i.e. infection) Perform with CCLAD Contraindications: Patients with unusually thin palatal tissue Patients that cannot tolerate 3-4 minute administration time Procedures requiring more than 90 minutes

53 Anterior Middle Superior Alveolar Advantages Anesthesia of multiple max teeth with a single injection Good injection for periodontal debridement Simple Allows for accurate esthetic procedures since smile line is not affected No postoperative anesthesia of the lip Atraumatic High success

54 Anterior Middle Superior Alveolar Disadvantages Long administration time Can cause operator fatigue Uncomfortable if administered to rapidly Can cause ischemia Avoid high concentration anesthetics (4%) DO NOT do with a 1:50,000 epi May require supplemental anesthesia for centrals and laterals Aspiration:, 1%

55 Anterior Middle Superior Alveolar Technique 30- gauge short recommended Area of insertion: on the hard palate, halfway from the midpalatal suture to the contact point between the first and second premolars Target area: palatal bone at the injection site

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58 Anterior Middle Superior Alveolar Technique Landmarks: Midpalatal suture Contact between the first and second premolars

59 Anterior Middle Superior Alveolar Technique Procedure Assume the position Right handed» 9 or 10 o clock facing the patient Left handed» 2 or 3 o clock facing the patient Prepare the tissue

60 Anterior Middle Superior Alveolar Technique Procedure Bevel against the epithelium for prepuncture technique Have patient supine with slight hyperextension of head and neck. Apply the bevel of the needle toward the epithelium and cover with a cotton tipped applicator with topical Apply pressure to create seal Initiate delivery of local anesthetic Maintain 8-10 seconds. Wait 30 sec to obtain superficial anesthesia

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63 Anterior Middle Superior Alveolar Technique Procedure Slowly advance needle until contact is made with bone

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65 Anterior Middle Superior Alveolar Technique Procedure Aspirate Deposit ml at a rate of 0.5 ml/min Injection takes 3-4 min Withdraw Safe the needle Wait 3-5 minutes before commencing treatment

66 AMSA Video

67 OraVerse OraVerse Phentolamine Mesylate (0.4mg/1.7ml) Vasodilator used in medicine since 1952 Blocks action of epinephrine Was initially developed as an impotence drug (ED) Led to long term erections Local anesthesia reversal agent does NOT reverse local anesthetic

68 Recovery time OraVerse

69 OraVerse How to use 0.4mg/1.7ml solution per cartridge Administered 1:1 volume ratio 1 cartridge of OraVerse for each cartridge of LA delivered Delivered to the same injection site Maximum recommended dose 2 cartridges for adults and children 12 years and older 1 cartridge for patients 6-11 years old and over 66 lbs. ½ cartridge for children 6-11 years old and lbs. Administered at the end of the procedure when anesthesia is no longer needed

70 OraVerse Pediatric Safety Profile Not recommended for children under age 6 Not recommended for children weighing less that 33 lbs. In children lbs. the maximum OraVerse dose is ½ cartridge (0.2mg)

71 OraVerse Mechanism of Action Alpha-adrenergic block of short duration which results in vasodilation of vascular smooth muscle Increased blood flow to the area of injection results in increased uptake of LA form the area of injection and distribution, metabolism and elimination

72 Safety OraVerse Most common adverse effects Post op pain Tachycardia or bradycardia Headache Contraindications Avoid use in patients with cardiovascular disease May cause cardiac arrhythmias Not recommended in children under age 6 or less than 33 lbs. OraVerse is NOT an antidote for LA overdose

73 Do we wait long enough? How long does it REALLY take for pulpal anesthesia to develop? 2013 Dr. Stanley F. Malamed

74 Can we improve the curve with drugs such as Articaine? Sadly NO.

75 Can we improve the curve by buffering the LA solution? Happily YES

76 Buffering Local Anesthetics are weak bases LA cartridges are formulated in an acidic solution to: make the LA soluble Inhibit oxidation and increase shelf life Lidocaine HCL with epinephrine : ph = 3.9 Mepivacaine HCL plain: ph = 5.5 Physiologic ph = ( ) Acidic solution creates Pain on injection More delayed onset

77 Buffering Adding Sodium Bicarbonate to the LA solution to increase its ph towards normal physiological ph Onset mixing pen by Onpharma Increasing the ph increases the amount of free base (unionized) form of the LA which is able to cross the neurolemma A change from a ph of 3.5 (LA with epi) to 7.4 will create a 6000 fold increase in the free base

78 Buffering Buffering MUST occur just prior to injection LA will become a weak base and precipitate out of solution CO 2 is created which increases the comfort of the injection Advantages More rapid onset of action Improved comfort of injection More profound anesthesia

79 Onset video

80 Intranasal Local Anesthesia in the Maxilla Kovacaine Mist TM (St Renatus) 3% Tetracaine and 0.05% Oxymetazoline Sprayed on the nasal mucosa (R and L nares), the anesthetic diffuses to the maxillary dental plexus to provide Maxillary Anesthesia From #4 to #13 84% success first molar to first molar Utilized by ENT s for nasal procedures Estimated at $20/dose Supposed to receive FDA approval this Fall (2013) Phase I & II safety and efficacy studies are already complete